wcsnrtombs

WCSNRTOMBS(3)              Linux Programmer's Manual             WCSNRTOMBS(3)

NAME
       wcsnrtombs - convert a wide-character string to a multibyte string

SYNOPSIS
       #include <wchar.h>

       size_t wcsnrtombs(char *dest, const wchar_t **src, size_t nwc,
                         size_t len, mbstate_t *ps);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       wcsnrtombs():
           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:
               _GNU_SOURCE

DESCRIPTION
       The  wcsnrtombs()  function  is  like the wcsrtombs(3) function, except
       that the number of wide characters to be converted, starting  at  *src,
       is limited to nwc.

       If  dest  is  not  NULL, the wcsnrtombs() function converts at most nwc
       wide characters from the wide-character  string  *src  to  a  multibyte
       string  starting  at dest.  At most len bytes are written to dest.  The
       shift state *ps is updated.  The conversion is effectively performed by
       repeatedly  calling  wcrtomb(dest, *src, ps), as long as this call suc-
       ceeds, and then incrementing dest by the number of  bytes  written  and
       *src by one.  The conversion can stop for three reasons:

       1. A wide character has been encountered that can not be represented as
          a multibyte sequence (according to the  current  locale).   In  this
          case,   *src  is  left  pointing  to  the  invalid  wide  character,
          (size_t) -1 is returned, and errno is set to EILSEQ.

       2. nwc wide characters have been converted without encountering a  null
          wide  character (L'\0'), or the length limit forces a stop.  In this
          case, *src is left pointing to the next wide character  to  be  con-
          verted, and the number of bytes written to dest is returned.

       3. The  wide-character  string has been completely converted, including
          the terminating null wide character (which has the  side  effect  of
          bringing  back *ps to the initial state).  In this case, *src is set
          to NULL, and the number of bytes written to dest, excluding the ter-
          minating null byte ('\0'), is returned.

       If  dest is NULL, len is ignored, and the conversion proceeds as above,
       except that the converted bytes are not written out to memory, and that
       no destination length limit exists.

       In  both  of  the  above cases, if ps is NULL, a static anonymous state
       known only to the wcsnrtombs() function is used instead.

       The programmer must ensure that there is room for at least len bytes at
       dest.

RETURN VALUE
       The  wcsnrtombs() function returns the number of bytes that make up the
       converted part of multibyte sequence,  not  including  the  terminating
       null byte.  If a wide character was encountered which could not be con-
       verted, (size_t) -1 is returned, and errno set to EILSEQ.

ATTRIBUTES
       For  an  explanation  of  the  terms  used   in   this   section,   see
       attributes(7).

       +-------------+---------------+-------------------------------+
       |Interface    | Attribute     | Value                         |
       +-------------+---------------+-------------------------------+
       |wcsnrtombs() | Thread safety | MT-Unsafe race:wcsnrtombs/!ps |
       +-------------+---------------+-------------------------------+

CONFORMING TO
       POSIX.1-2008.

NOTES
       The  behavior  of  wcsnrtombs() depends on the LC_CTYPE category of the
       current locale.

       Passing NULL as ps is not multithread safe.

SEE ALSO
       iconv(3), mbsinit(3), wcsrtombs(3)

COLOPHON
       This page is part of release 4.15 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.

GNU                               2017-09-15                     WCSNRTOMBS(3)
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